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Owners increase Gen 3 MPG by 4.3 on EPA Website

Discussion in 'Gen 3 Prius Fuel Economy' started by Glider, Jul 20, 2009.

  1. Glider

    Glider New Member

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    The EPA/DOE website that provides data on driver's MPGs has boosted the average MPG from 48.1 two weeks ago to 52.4 today - an increase of 4.3 MPG! This comes from increasing from 4 to 11 the number of people reporting their mileage during the past 2 weeks.

    Note that the 2009 Prius is also reporting fantastic results at 50.5 MPG, and the earlier models are not far behind!

    Way to go! I hope others will join the website; it only takes a few minutes to register at:

    www.fueleconomy.gov

    :tea:
     
  2. quantumslip

    quantumslip Member

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    you might want to rename this post subject, it's kind of misleading (i though the official EPA numbers were increased)
     
  3. Glider

    Glider New Member

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    I clarified it by editing the title above - not sure if this is how you do it.
     
  4. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Excellent change, thanks!

    The problem is it will take a while before we see a large enough population of Prius reports to see what is going on. A few early posters can shift the numbers until we see a larger population of reports:

    • 53.2 MPG - averaging all reported values (we don't have raw numbers)
    • 54.1 MPG - averaging all but the lowest and highest
    We have three 2010 Prius records over in MyHybridCar.com and they are also in the middle, 53 MPG range:

    • 53.1, 53.3 and 53.8
    Bob Wilson
     
  5. nineinchnail1024

    nineinchnail1024 New Member

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    I hate to be a Debbie Downer, but I tend to believe that the hypermilers who are already more enthusiastic about their prius are more likely to post on sites online. Still, my driving reflects the new numbers.
     
  6. bwilson4web

    bwilson4web BMW i3 and Model 3

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    In January 2006, a group of self-selected hypermilers left GreenHybrid to form CleanMPG. Once they had their own web milage recording system, many of them replaced their signatures and stopped updating their GreenHybrid records. From what I can tell at MyHybridCar and Ecomodder, the hypermiler crowd tends not to maintain parallel mileage records at least with tank-to-tank detail.

    Bob Wilson
     
  7. windstrings

    windstrings Certified Prius Breeder

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    These numbers could actually be more encouraging that first thought because we are comparing the older "broke in" prius's with the new "tight" prius's that will not achieve their maximum mileage for some time yet!.....

    Plus, it may be possible that people are comparing their "best" mileage from old charts when the weather was more mild verses the present hot temperatures that require frequent and intense use of the air conditioner!

    In other words, its hard to compare unless the variables of temperature, same driver styles, and break in condition of the engine are also equal with both cars.

    The gap between the two based on the logic I just presented should only get better and farther apart as time goes on and the fall milder temps come into play.
     
  8. Glider

    Glider New Member

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    True, probably. Also, need to collect enough data to simmer down the statistical fluctuations. Time will tell.
     
  9. krousdb

    krousdb NX-74205

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    I would agree that those more likely to post FE data on the web are the ones who are achieving better numbers. That is a major reason why they join or visit in the first place. Another reason that this data may be skewed is because the Gen III was released in the spring/summer. Remember all of the complaints about bad FE during the winter of 2003/2004 when the Gen II started hitting the road in large numbers? I expect the reported numbers to drop back down to 50 when winter 2009/2010 rolls around.
     
  10. Glider

    Glider New Member

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    Although the optimistic assessment due to higher temperature might be balanced by the pessimistic numbers that arise from the tightness of the not-yet-broken-in moving parts and drivers. I wonder if anyone knows why the 2009 G2 is reporting better numbers by 3-4 MPG than the G2 models from the earlier five years:

    '09 50.6 mpg
    '08 46.5
    '07 46.8
    '06 47.8
    '05 47.7
    '04 47.5

    Did they make a major improvement in the design that year?

    Cheers G2 :kiss: G3
     
  11. a priori

    a priori Canonus Curiosus

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    More likely it is because the sample size isn't large enough to be a fair comparison. If you look at how many people have reported, you'll see that the sample size is nearly an order of magnitude larger for each of the other years.
     
  12. Matt Herring

    Matt Herring New Member

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    I keep parallel mileage records on ecomodder.com and myhybridcar.com but only do it because the ecomodder sig is a 90 day sig and the myhybridcar sig is a lifetime sig. Thought it would be good to see both represented as their differences could be big during lower mileage winters. If it didn't take so much time to input my tank stats (on 2 websites and in 2 excel sheets I keep) I would probably do it on a few other sites too!

    I also recorded my mpg on the fueleconomy.gov site for my 2009 model. I certainly qualify for the "hypermiling crowd" and otherwise would not have done it if I had no interest in max mpg.
     
  13. reverai

    reverai New Member

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    Perhaps, but my average for the last 500 miles has been 52.7 per gallon with mostly city drive(60%-40%) but then my 2008 Prius has 35287 miles.

    Steve
     
  14. bwilson4web

    bwilson4web BMW i3 and Model 3

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    <AHEM>The price of gasoline doubled so efficient driving might have become more attractive ... even for Prius owners. The earlier years had ordinary gas prices so efficient driving was not so important.

    Bob Wilson
     
  15. Glider

    Glider New Member

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    Thanks. I was just puzzled because the EPA estimates were the same for all six G2 model years and certainly did not intend to suggest any monkey business. So far the possible reasons for this difference have been gas prices, smaller sample size for '09, and also I tried to see if the '09 data leaned toward warmer months but since they only give date of last update, not dates of all records, you can't tell much.

    Whatever the reasons, I think it is great that the last two model-years of the Prius are in the 50 mpg zone. Everybody wins and it is a great encouragement for other manufacturers to press on!!

    - g
     
  16. windstrings

    windstrings Certified Prius Breeder

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    Seems a rather large factor may be as to whether they have the package with the 17" wheels or not..... seems those folks should not enter their input unless that is stated.

    Gen II prius's were pretty much all on the same standard, but its common knowledge the 17" wheels steal approx 3 mpg at least.

    Of course, another factor is tire choice... some tires... especially the low profile choices or those that are wider don't care too much about rolling resistance.:rolleyes: